Portion sizes of ready meals and supermarket staples have increased in size, in some cases doubling, since 1990, according to an in depth report.

By Harry Wallop, Consumer Affairs Correspondent

11:56PM BST 19 Jun 2008

The average portion size of foods including sliced white bread, eclairs, chocolate mousses, lasagne ready meals, chicken curries and chips in take away outlets have increased over the last two decades.

The findings will re-open the debate about food companies fuelling the UK's increasing obesity problem.

The report from the Food Standards Agency found that the average size of an individual beef lasagne ready meal, for instance, has increased by from 250 grammes in 1990 to between 320 grammes and 500 grammes now.

A medium slice of white bread now weighs 40 grammes – up from 30 grammes in 1990.

Chocolate mousses have more than doubled from 60 grammes to 150 grammes, according to the report, which analysed historic and current data on a wide range of food in both supermarkets and restaurants.